| Abbreviation | Definition |
|---|---|
| PVVR | Portland, Vancouver and Vitebsk Seaway Railroad (BNSF Railway) |
| PW | Pilot Wheels |
| PW | Pittsburgh & West Virginia Railroad |
| PW | Providence and Worcester Railroad |
| PW | Providence and Worcester Railroad Company |
| PWCX | Inland Cement Limited |
| PWFX | Port Rail Services |
| PWRX | Pacific Western Resin Company |
| PWRZ | Providence and Worcester Railroad |
| PWRZ | Providence and Worcester Railroad Company |
| PWV | Norfolk Southern Railway Company |
| PWV | Pittsburgh & West Virginia Railroad |
| PWV | Pittsburgh & West Virginia Railway (Norfolk Southern Railway) |
| PWX | Providence & Worcester Railroad Company |
| PXCU | Phoenix Container Liners Limited |
| PXCZ | Phoenix Container Liners Limited |
| QBT | Quincy Bay Terminal |
| QBT | Quincy Bay Terminal Company |
| QC | Canadian Pacific Railway |
| QC | Quebec Central Railway |